Sex pheromone of the French black cutworm moth, Agrotis ipsilon (Lepidoptera: Noctuidae): Identification and regulation of a multicomponent blend

The sex pheromone blend of a European strain of the black cutworm moth, Agrotis ipsilon (Hufnagel), was investigated. Chemical analyses of pheromone gland extracts from 4- to 8-day-old females showed that individual isolated glands contained only very small amounts of pheromone. High-resolution gas chromatography combined with mass spectrometry (CC-MS) analyses showed the presence of cis-7-dodecenyl acetate (Z7-12:Ac), cis-9-tetradecenyl acetate (Z9-14:Ac), cis-11-tetradecenyl acetate (Z11-14:Ac), cis-11-hexadecenyl acetate (Z11-16:Ac), and cis-11-hexadecenol (Z11-16:OH) in biologically active pheromone gland extracts. Removing 27-12:Ac, Z9-14:Ac, or Z11-16:Ac from the complete gland extract by GC trapping techniques strongly reduced the attractiveness of the pheromone blend tested in a wind tunnel. Lack of cis-5-decenyl acetate (Z5-10:Ac) or Z11-16:OH did not affect the blend attractiveness. Chemical and behavioral analyses showed that pheromone components are produced during photophase, at least 2 hr before lights off. Quantitative data showed that decapitation inhibited the production of Z7-12:Ac, Z9-14:Ac, Z11-14:Ac, Z11-16:Ac, and Z11-16:OH, but production in decapitated females was stimulated in response to injection of synthetic Heliothis tea PBAN (pheromone biosynthesis activating neuropeptide) or A. ipsilon brain-subesophageal (Br-SEG) homogenates. Moreover, upon injecting BR-SEG homogenates, other minor components were detected, which were tentatively identified as cis-8-dodecenyl actetate (Z8-12:Ac) and Z5-10:Ac. Our study demonstrated that Z11-16:Ac is one of the main active components produced by the pheromone gland of this European population of A. ipsilon, in addition to Z7-12:Ac/Z9-14:Ac, which were investigated in a previous behavioral analysis. All these data strongly suggest that some polymorphism is present in pheromone communication in different strains of A. ipsilon.